/*
day463 
2020.12.3 
*/

#include<iostream>
#include<vector>
using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution {
public:
    TreeNode* mirrorTree(TreeNode* root) {
		if(!root) return nullptr;
		
		TreeNode *tem=root->left;
		root->left=root->right;
		root->right=tem;
		
		mirrorTree(root->left);
		mirrorTree(root->right);
		
		return root;
    }
};

int main()
{
	return 0;
}
